The communications industry shows a growing interest in using wireless communication technology to transmit data to and from remotely located devices, equipment, or machines. A cellular mobile radiotelephone (“CMR”) system or network can transmit data between a user and a remote device such as a vehicle, vending machine, utility meter, security alarm system, community antenna television (“CATV”) pay-per-view (“PPV”) terminal, etc. The user can obtain telemetry data from sensors or other data acquisition apparatus coupled to the device to remotely acquire information about the device's operations, operating status, or operating environment. The user can also send messages to the device via the CMR system, for exampling requesting specific information or controlling some aspect of the device's operation.
As an alternative to consuming the voice-carrying bandwidth of the CMR system, two-way communications between remote equipment and a central facility or other site can transmit on the CMR system's secondary channels or overhead control channels. That is, the control channels of a CMR system can support data communications with devices with minimal impact on person-to-person voice communications. In its role for voice communications, an overhead control channel transmits data that controls communication actions of mobile and portable radiotelephones operating on the CMR system. An overhead control channel, which typically supports digital communication, can be a paging channel or an access channel, for example. The cellular system uses the control channels to communicate information for handling incoming and outgoing call initiations between the cellular system and a cellular customer. Since these control channels generally have greater message handling capability than the cellular system needs for handling voice traffic, they can convey telemetry data without impairing voice communications.
In this manner, bidirectional data communication with a telemetry system, such as a monitor, controller, sensor, or similar device coupled to a data source, proceeds on the overhead control channel. Such a telemetry system may comprise a CMR transceiver that sends and receives data on the overhead control channel. The term “telemetry system,” as used herein, refers to a system that acquires, senses, or otherwise obtains information from a remote machine, apparatus, device, or other source and transmits the information to a receiving station or site for recording, analysis, viewing, or other purpose. An individual or a computer can request and obtain position, movement, or geographic data from a telemetry system attached to a vehicle by communicating on the overhead control channels of the CMR system, for example.
An application of wireless telemetry that often has little tolerance for such delays is remote monitoring or control of a vehicle. If a vehicle owner needs to find his or her vehicle, the owner may lack the patience or the time to wait a significant period of time to receive the vehicle's location via a conventional communication line.
Another problem with some conventional telemetry systems that monitor vehicles is that they may fail to provide a sufficient level of functional capability. Such a telemetry system may monitor a vehicle's operation and provide notification to a remote owner upon an occurrence of a designated event, such as a theft attempt. However, the telemetry system may fail to consider the circumstances surrounding the event or other events that preceded or followed that event. In other words, conventional technology for vehicle telemetry may not provide an adequate level of processing or analysis of sensor data. Without adequate processing of sensor data, a user of the telemetry system may be overwhelmed with extraneous data or false alarms. The data of interest to the user may be buried in the extraneous data and not readily apparent. Thus, telemetry systems based on conventional technology may not adequately highlight operating conditions or events of potential concern to the vehicle's owner.
To address these representative deficiencies in the art, what is needed is an improved capability for monitoring a vehicle's location via wireless telemetry.